Muscle-Wasting Disease in Elephant Seal Pups
- Pathology
Abstract
A field study addressing causes of mortality in freshly dead northern elephant seals (Mirounga angustirostris, Gill, 1866) was conducted on San Miguel Island, California, in February 2015. Necropsies were performed on 18 pups ranging in age from stillbirths to approximately 7 to 8 weeks. The primary gross diagnoses in these pups included trauma, myopathy, starvation/emaciation, infections, congenital anomalies, and perinatal mortality. However, 6 (33%) had a previously unrecognized myopathy characterized by multiple white streaks that were most obvious within the inner layer of the abdominal wall and the small innermost ventral intercostal muscles. Following histological examination, 2 more pups from San Miguel Island and 6 pups from The Marine Mammal Center (Sausalito, California) were found to have similar lesions. Histologically, the lesions within the skeletal muscles were characterized by a multifocal polyphasic, mild to severe, acute to subacute necrotizing myopathy with mineralization. Acute necrosis and degeneration characterized by pyknotic nuclei, eosinophilic cytoplasm and cytoplasmic vacuolization were found in smooth muscle myocytes within the urinary bladder and digestive system. Degeneration of myocytes was present in the tunica media of a few small- to medium-sized vessels and was characterized by a vacuolar degeneration and occasionally necrosis. This condition has been termed multifocal necrotizing myopathy. A cause of this myopathy was not identified.
Spraker, T.R., Kuzmina, T.A., Lyons, E.T., DeLong, R.L., Simeone, C. and Veeramachaneni, D.R., 2019. Multifocal Necrotizing Myopathy in Northern Elephant Seal (Mirounga angustirostris) Pups, San Miguel Island, California. Veterinary pathology, 56 (1, January), pp.143-151.
Related Publications
{"image":"\/Animals\/Wild\/Bottlenose dolphin\/bottlenose-dolphins-leaping-shutterstock.jpg","alt":"dolphins leaping out of the water","title":"Fresh Water Skin Disease in Dolphins","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/fresh-water-skin-disease-in-dolphins","label":"Research Paper"}
{"image":"\/Animals\/Wild\/Sea otter\/cropped-images\/sea-otter-grooming-head-shutterstock-22-86-3617-2826-1616709449.jpg","alt":"sea otter grooming","title":"Parasitic Skin Disease in Threatened Southern Sea Otters","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/parasitic-skin-disease-in-threatened-southern-sea-otters","label":"Research Paper"}
{"image":"\/Animals\/Wild\/Other species\/cropped-images\/galapagos-sea-lion-shutterstock-954-376-2988-2334-1617750524.jpg","alt":"Galapagos sea lion","title":"Mycoplasmas in Galapagos Sea Lions and Their Association with Other Respiratory Pathogens","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/occurrence-of-mycoplasmas-in-galapagos-sea-lions","label":"Research Paper"}
Mycoplasmas in Galapagos Sea Lions and Their Association with Other Respiratory Pathogens
Read More{"image":"\/Animals\/Wild\/Other species\/cropped-images\/stejnegers-beaked-whale-photo-c-marc-webber-0-0-949-742-1618440217.jpg","alt":"Stejneger's beaked whales","title":"Stejneger's Beaked Whale Strandings in Alaska, 1995\u20132020","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/stejnegers-beaked-whale-strandings-in-alaska-1995-2020","label":"Research Paper"}
Related News
{"image":"\/Animals\/Wild\/Gray whale\/cropped-images\/2025-03-30-gray-whale-BlackSandsBeach-c-the-marine-mammal-center-206-0-1270-992-1743546220.jpg","alt":"stranded gray whale","title":"Experts respond to a dead gray whale in the Marin Headlands as sightings of the species increase in San Francisco","link_url":"https:\/\/www.marinemammalcenter.org\/news\/experts-respond-to-a-dead-gray-whale-in-the-marin-headlands-as-sightings-of-the-species-increase-in-san-francisco","label":"Press Release","date":"2025-04-01 02:00:00"}
Experts respond to a dead gray whale in the Marin Headlands as sightings of the species increase in San Francisco
April 1, 2025
Read More{"image":"\/Animals\/Wild\/Gray whale\/cropped-images\/gray-whale-tail-sf-skyline-by-darrin-allen-c-the-marine-mammal-center-60-0-624-487-1719870230.jpg","alt":"gray whale tail seen above water with San Francisco skyline in the distance","title":"Mercury News: Lots of Gray Whales Are Swimming Under the Golden Gate Bridge into San Francisco Bay. Why?","link_url":"https:\/\/www.marinemammalcenter.org\/news\/mercury-news-lots-of-gray-whales-are-swimming-under-the-golden-gate-bridge-into-san-francisco-bay-why","label":"In the News","date":"2024-06-24 02:00:00"}
Mercury News: Lots of Gray Whales Are Swimming Under the Golden Gate Bridge into San Francisco Bay. Why?
June 24, 2024
Read More{"image":"\/Animals\/Wild\/Bottlenose dolphin\/cropped-images\/bottlenose-dolphins-leaping-shutterstock-391-0-3448-2693-1605038111.jpg","alt":"two dolphins leaping out of the waves","title":"\u201cThe Dolphin Dilemma\u201d Documentary Makes Waves On Film Festival Circuit","link_url":"https:\/\/www.marinemammalcenter.org\/news\/the-dolphin-dilemma-documentary-makes-waves-on-film-festival-circuit","label":"News Update","date":"2024-05-30 02:00:00"}
“The Dolphin Dilemma” Documentary Makes Waves On Film Festival Circuit
May 30, 2024
Read More{"image":"\/Animals\/Wild\/Gray whale\/cropped-images\/gray-whale-muir-beach-c-the-marine-mammal-center-66-2-1533-1198-1617991349.jpg","alt":"gray whale in shallow water","title":"LA Times: Starvation Has Decimated Gray Whales - Can the Giants Ever Recover?","link_url":"https:\/\/www.marinemammalcenter.org\/news\/la-times-starvation-has-decimated-gray-whales-can-the-giants-ever-recover","label":"In the News","date":"2024-03-27 02:00:00"}
LA Times: Starvation Has Decimated Gray Whales - Can the Giants Ever Recover?
March 27, 2024
Read More